Technical Field
The present disclosure relates to continuous feed printers, and more particularly, to a portable label or thermal printer configured to perform self-calibration in response to indicia encoded on media.
Background of Related Art
Portable or desktop printers used in many settings, e.g., in warehouses, in industrial and manufacturing environments, by shipping services, in the vending and gaming industries, and in retail establishments for ticket printing and inventory control. Ideally, portable printers weigh only a few pounds, and some are small enough to be easily carried during use and/or easily attached to a buckle or a harness-type device. This enables the user to print labels or receipts on demand without having to retrieve a printed label from a printing station. Because the printer is portable, the printer may include a power source, such as a disposable or rechargeable battery, and may additionally communicate with a host terminal or network connection via a wireless interface, such as a radio or optical interface. A portable printer may utilize sheet-fed media, or, more popularly, continuous-feed media, e.g., rolls of paper, labels, tags, and the like. Portable printers commonly employ direct thermal transfer techniques, whereby thermochromic media passes over a thermal print head which selectively heats areas of the media to create a visible image. Also popular are thermal transfer printers which employ a heat-sensitive ribbon to transfer images to media.
A continuous feed printer is particularly suitable for printing onto stock material which may include, but is not necessarily limited to, labels, receipts, item labels, shelf labels/tags, ticket stubs, stickers, hang tags, price stickers, and the like. Label printers may incorporate a media supply of “peel away” labels adhered to a coated substrate wound in a rolled configuration. Alternatively, a media supply may include a plain paper roll suitable for ink-based or toner-based printing. Continuous media is typically supplied in rolls, and is available in various widths. The roll media may be wound around a generally tubular core which supports the roll media. The core may have a standard size, or arbitrarily-sized inner diameter. In use, the media is drawn against a printing head, which, in turn, causes images to be created on the media stock by, e.g., impact printing (dot matrix, belt printing), by localized heating (direct thermal or thermal transfer printing), inkjet printing, toner-based printing, or other suitable printing methods.
Portable or thermal printers may be designed for use with many different types of print media. Each different type of print media may have particular properties which affect the printing process, for example, media type (direct thermal, thermal transfer, impact, etc.), label length, label width, thermal transfer characteristics, surface texture, color, manufacturing date and lot number, and so forth. When a user loads media into a printer, he or she may need to provide, typically using a control panel or other user interface device, one or more media parameters to the printer to ensure that images printed on the media are properly rendered. For example, if a thermal printhead provides insufficient heat to a particular type of thermal media, the resulting label may appear washed out or unreadable. The manual entry of media parameters may be error-prone. In addition, if a user fails to enter the necessary media parameters, labels may be wasted and/or other inefficiencies or unforeseen consequences may ensue.